1. Field of the Invention
The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus for forming an image on a recording medium using an electrophotographic process. The present invention is suitably applicable to a copying machine, a printer (e.g., a light-emitting diode (LED) printer, a laser beam printer), a facsimile machine, and a word processor.
2. Description of the Related Art
A process cartridge is known as a cartridge type used in a conventional image forming apparatus using the electrophotographic image forming process. In the process cartridge, a drum and a developing unit, which includes a developing roller that acts on the drum and stores a developer (toner) to be used for image formation, are integrated with each other. A developing cartridge is also known as the cartridge type, which is configured to be independent of the drum and include only the developing unit. These types of cartridges allow a user to perform maintenance work for the apparatus by himself/herself without relying on a service engineer. Thus, these cartridges have been widely employed in a variety of electrophotographic image forming apparatuses.
Further, there is known a technique in which an image forming apparatus is configured to include a movable member that places a process cartridge or a developing cartridge therein and allow a user to pull out the movable member from inside the main body of the image forming apparatus to a predetermined position outside the main body so that the user can perform various cartridge replacement works. According to this technique, the user can easily replace the developer, for example.
Furthermore, as discussed in Japanese Patent No. 3608767 or Japanese Patent Application Laid-Open No. 2013-228635, there is known a method in which the movable member is provided with a cleaning member for cleaning an exposure portion of an exposure device that is used in the electrophotographic image forming process, so that the exposure portion is cleaned by the cleaning member when the movable member moves. In the method discussed in Japanese Patent Application Laid-Open No. 2013-228635, the movable member includes a recessed portion for collecting dust particles removed by the cleaning member.
In the above-described conventional techniques, the following problems arise. When the movable member is repeatedly moved and the cleaning member repeatedly performs the cleaning operation to clean the exposure portion, the cleaning member may deteriorate, leading to a decrease in its cleaning capability. Further, in the configuration discussed in Japanese Patent Application Laid-Open No. 2013-228635, in which the dust particles removed by the cleaning member are collected in the recessed portion provided in the movable member, once the recessed portion has been filled with the collected particles, it becomes unfeasible to collect dust particles in the recessed portion even when the particles are removed by the cleaning member. In these cases, the cleaning capability of the cleaning member may decrease after the cleaning member has performed the cleaning operation for a certain period of time.
Accordingly, maintaining the cleaning capability of the cleaning member for a long time is required in the above-described conventional configurations.